There are plenty of reviews of Avengers II: Age of Ultron out there (Variety, The Guardian, and so on). So I’ll just quickly say, if you liked the first one, you’ll probably enjoy this one. Having said which, I probably won’t see the third one (even less likely if Whedon’s directing).
Also, just a thought [SPOILER ALERT], having an aircraft carrier appear basically out of nowhere is basically my interpretation of a deus ex machina. I felt like it gave the protagonists an easy out from a hard question that the plot was asking them, and because of that the movie suffered.
Oh, and a second thing; that missing scene where Thor goes to find the meaning of his dream? Would have helped if it was included.